The success of subunit vaccines has been hampered by the problems of weak or short-term immunity and the lack of availability of nontoxic, potent adjuvants. It would be desirable to develop safe and efficient adjuvants with the aim of improving the cellular immune response against the target antigen. In this study, the targeting and sustained release of simple nanoliposomes containing Lycium barbarum polysaccharides (LBP) as an efficacious immune adjuvant to improve immune responses were explored. LBP liposome (LBPL) with high entrapment efficiency (86%) were obtained using a reverse-phase evaporation method and then used to encapsulate the model antigen, ovalbumin (OVA). We demonstrated that the as-synthesized liposome loaded with OVA and LBP (LBPL-OVA) was stable for 45 days and determined the encapsulation stability of OVA at 4°C and 37°C and the release profile of OVA from LBPL-OVA was investigated in pH 7.4 and pH 5.0. Further in vivo investigation showed that the antigen-specific humoral response was correlated with antigen delivery to the draining lymph nodes. The LBPL-OVA were also associated with high levels of uptake by key dendritic cells in the draining lymph nodes and they efficiently stimulated CD4 + and CD8 + T cell proliferation in vivo, further promoting antibody production. These features together elicited a significant humoral and celluar immune response, which was superior to that produced by free antigen alone.

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Ethylene is an important chemical raw material and with the increasing consumption of petroleum resources, the production of ethylene through the calcium carbide acetylene route has important research significance. In this work, a series of bimetallic catalysts with different Cu/Ni molar ratios are prepared by co-impregnation method for the hydrogenation of calcium carbide acetylene to ethylene. The introduction of an appropriate amount of Cu effectively inhibits not only the formation of ethane and green oil, thus increasing the selectivity of ethylene, but also the formation of carbon deposits, which improves the stability of the catalyst. The ethylene selectivity of the Ni–Cu bimetallic catalyst increases from 45% to 63% compared with the Ni monometallic counterpart and the acetylene conversion still can reach 100% at the optimal conditions of 250 °C, 8000 mL·g−1·h−1 and V(H2)/V(C2H2) = 3. X-ray diffraction and transmission electron microscopy confirmed that the metal particles were highly dispersed on the support, High-resolution transmission electron microscopy and H2-Temperature programmed reduction proved that there was an interaction between Ni and Cu, combined with X-ray photoelectron spectroscopy and density functional theory calculations results, Cu transferred electrons to Ni changed the Ni electron cloud density in NiCux catalysts, thus reducing the adsorption of acetylene and ethylene, which is favorable to ethylene selectivity.

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